Team NZ said the conditions yesterday - 12-14 knots - were right on the cusp of making the move a good one.
"It was looking light but, unfortunately, when we got there [the first mark] it was a bit quicker breeze," said Team NZ skipper Dean Barker yesterday. Asked if the code zero had added to their drag, Barker said: "It certainly wasn't helpful but I don't think that is the reason they rolled over us."
Code zeroes are well known as a kind of hybrid power booster. Typically used under 10 knots, they are a sort of cross between a genoa and a spinnaker and provide additional power when traditional sails are slow.
Team NZ tactician Ray Davies defended its use: "It wasn't a surprise that they elected to not have it up and then hoist it down the run," he said. "We talked about that but we felt that the breeze was soft enough to be into the code zero straight away."
Davies said Oracle's positioning on the line at the start had contributed more to the US syndicate's fast start than the use of the code zero.
"The momentum they had at the start, I don't think the code zero made any difference to them rolling us," he said, explaining that the New Zealand boat had set up to leeward.
"The weather end was biased, so we gave up too much line bias to start to leeward."
However, Davies believed the Kiwis did better with the code zero on the downwind leg than they would have without it.
"I think we were gaining on them at that point," he said.
"They had slipped away in a little bit of pressure and once we deployed the code zero, we stopped the rot and probably made a slight gain from that point."
Barker said: "We have got some little tweaks to do now, but nothing dramatic.
"We don't need to make massive changes. The boat is going well."
He also said the team would not be playing the postponement card to make big crew and boat changes, as Oracle had done earlier.
"I don't imagine we will need to use the card unless we run into some issues out there or something we want to change in the configuration of the boat. We know our boat well and what we have to do to win a race.
"We are up against a very strong team who are not making mistakes. In the early part of this series, it was us who were not making mistakes."
Asked what message he'd send to nerve-frazzled Kiwis, Barker said: "Have the same thing we do - belief in the team."